Centrifugal oil cleaner, including a cylindrical filter



D. MORE June 12, 1956 CENTRIFUGAL OIL CLEANER, INCLUDING A CYLINDRICA-LFILTER Filed Maron 4, 1953 mm\\\\\\\\ l United States Patentfificel2,750,107l Patented June 12, 1956 CENTRIFUGALVOIL CLEANER, rNcLUnlNGACYLINDRICAL FILTER t David lMore, Scotstoun, Glasgow, Scotland,assignor, .lby

mesneassignments, to The Glacier Metal Company Limited, Alperton,Wembley, England, a corporation f Great Britain Application March 4,1953, Serial No. 340,252 Claims priority, application Great BritainOctober 2, 19.52 4 claims. (Cl. zes- 2) This invention relates tocentrifugal oil cleaners.

Intheinterest of brevity we shall hereafter assume that the liquid to becleaned is fuel oil as lused fin compression ignition engines, butessentially the system is equally applicable to the cleaning oflubrication oil `orfother liquids. i

Experience has shown that the most leffective cleaner for fuel oil is acentrifuge including a `drum driven mechanically or electrically, or byjet'reactionas described Otherwise, the initial flow of fuel will beunfiltered, and

`there is also a great danger that any loose dirt in the centrifuge drummay be carried over and "cause lsevere 'wear to the engine injectionequipment.

There may be loose vparticles of dirt inthe centrifuge `drum if the dirtconsists of sandy material Without any gunimy constituent to bind itfirmly to the drurn wall; rlhe solvent properties of the fuel oil andvibrationtend'to loosen the sandy cake from the vertical wall when -thedrum is at rest.

Engines applied to road vehicles are subjected to frequent stopping andstarting, and it is 'undesirablein applications of this class to have toemploy anelaborate automatic gear toprovide the delay period duringwhich drum speed is built'up before the fuel starts to flow. A

The .present invention has for an object to provide a centrifuge whichcan deliver finely filtered fuel immediately on starting.

According to the invention, in a Acentrifugal oil cleaner the centrifugeincludes a rotatable drum and filter means so arranged that oil iiowingfrom the centrifuge drum passes through the filter means 4in accntripetal direction.

The drum may be fixed to,orrotatable with,"a`sp'indle formed with inletand outlet passageways or ducts terminating in inlet and outlet openingsthrough which oil is conducted into and out of the drum. Alternatively,the spindle may be fixed, the drum being supported by and rotatableabout a fixed shaft. In another alternative the drum may be supported byand rotatable about two fixed stub shafts.

The inlet passageways or duct may terminate in at least one stand pipeparallel to and radially spaced from the axis of the drum, the inletopening being the open end of the stand pipe which is preferably broughtnear the top of the drum.

The outlet opening may be at least one port in the wall of the spindle,or of the shaft, the filtering element being in the form of a cylinderco-axial with and surrounding the spindle or the shaft.

In a preferred construction, the centre portion of the spindle is formedwith a broad annular groove from the bottom of which an opening leads tothe discharge passageway or duct, a perforated sleeve surrounds thespindle, and a cylindrical filtering element surrounds the sleeve.Thefiltering element rotates with the drum at a rotational speed'suchthat the centrifugal force is great enough to prevent dirt deposits fromforming on said element, and also great enough to throw off the dirtdeposits which may have formed temporarily on said element during thestartingup period.

The dirt collects on the inside of the drum and can be scraped out atconvenient cleaning-periods. The filter- -ing element, beingself-cleaning, requires no attention.

The filtering element may be made of a material hav, ing smallerinterstices than is practicable ina conventional oil cleaner, because inconventional cleaners the deposits of `fine dirt which would build upona fine grade element would be too dense and would quickly slow down landeventually block the flow through the element.

The filtering element may consist of dense felt, paper, porous metal,ceramic, etc., provided `these are constructed to resist :break-up ordisplacement when subjected lto -a high centrifugal force.

'The centrifuge operates well with a centrifugal force of 600 g at thefiltering lelement and 1000 g at the mean radius of the dirt collectionzone, but these values -are not critical, and should be regarded only aspreferred minim for steady conditions.

`Only one fuel feed pump is required in conjunction with an oil cleaneras described because the output pressure from this pump can supply boththe force for driving the drum and also the force to feed the fuel from`the centri- `fuge to the engine injection pump.

A practical 'embodiment of the invention in which the ydrum is rotatedby jet reaction is illustrated inthe accompanying drawings in which Fig.l is a section on a horizontalplane through a filter, and Fig. 2 is asection through a'filter on the line 2 2 of Fig. l. u -In the drawings,1 denotes a casing containing -a drum 2 `fixed to a spindle 3 formedwith an axial inlet passageway or duct 4 connecting with inlet pipes 5,and formed withan axial oil outlet passageway orduct 6 open to adischarge 'connection 7 on the top of the lcasing 1. The .passageways 4and 6 are in communication with `the 'exterior o f the casing throughextensions 8 and 9 of the spindle, said extensions serving as journalssupported in bearings in the casing 1. The central portion of thespindle 3 is provided with a broad annular groove 15 surrounded byaperforated sleeve 10 encased in a cylindrical filtering element 11. l12denotes stand pipes open at the topend tothe interior of the drum andterminating at the lower` end in reaction nozzles of vwhich `'one isillustrat'ed at 13. V14 denotes a deposit of dirt on the inside of thedrum 2. The 4passageway 4 is open to an oil supply connection 16. y

ln'practice, fuel is normally drawn 'from a fuel tank by anengine-driven feed pump which may be of the spring-loaded plunger typegiving a nearly constant delivery pressure over a wide range of enginespeeds. The fuel is fed under pressure to the drum 2 and enters the drum2 through the inlet passageway 4 and the inlet pipes 5. As the drumrotates, centrifugal action separates and deposits dirt Von the drumwall.

Cleaned fuel for the engine passes through the filtering element 11 andout through the perforated sleeve 10 and the outlet passageway 6 in thespindle 3. The remainder of the fuel passes out through the pipes 12 andreaction nozzles 13. The fuel from the nozzles 13 drains directly backto the fuel tank.

Before reaching the engine, fuel from the cleaner may be conductedthrough an orifice or spring-loaded valve to reduce the fuel pressure toa convenient value.

An advantage associated with a reaction jet driven oil cleaner asdescribed lies in the fact that on shut down of the cleaner an automaticreversal of flow takes place through the ltering element. The owreversal occurs when the engine stops and the feed pump has ceased todeliver fuel. The drum momentum, however, causes the drum to spin for ashort time before coming to rest. During this period the moving nozzlesact as a pump and cause the oil to ow back out of the element, thusflushing the element and supplementing the normal centrifugalself-cleaning action.

An advantage connected with the use of stand pipes is that they preventdirt, which may become loosened from the drum walls by the solventproperties of the fuel when the drum is at rest, from sliding down intothe inlet and the jet passages.

Under any given operating conditions one series of inspection checks onthe rate of dirt accumulation in the drum will indicate the desirableregular cleaning interval.

A cleaner as described can be used for the full ow or by-pass filtrationof lubricating oil or other liquids.

What is claimed is:

1. An oil cleaner comprising a rotatable drum, an upright spindleextending axially through the drum and to which the drum is fixed forrotation therewith on an upright axis, oil inlet pipes in the drumparallel to the spindle and radially spaced therefrom and from theperiphery of the drum, an oil inlet passageway in the lower portion ofthe spindle communicating with said oil inlet pipes for the delivery ofoil to be cleaned to the interior of said drum, said oil inlet pipesterminating with open ends in the upper portion of the drum, an outletpassageway for clean oil in the upper portion of said spindle andopening into the drum above the oil inlet passageway in the spindle, acylindrical filtering element surrounding the spindle arranged to filteroil flowing to the opening of the outlet passageway for clean oil, andmeans for rotating said drum, whereby the oil to be cleaned anddelivered through said pipes into the upper portion of the drum issubjected to the centrifugal action produced by the rotation of the drumfor the separation of dirt, which accumulates on the inner periphery ofthe drum, and oil owing to the opening from the drum to the outletpassageway in the upper portion of the spindle is passed through saidcylindrical filtering element.

2. An oil cleaner as claimed in claim 1, including a perforated sleevesurrounding the major portion of the spindle in the drum and in spacedrelation thereto, the said opening of the outlet passageway leading fromthe space between the spindle and the perforated sleeve, and saidcylindrical filtering element encasing said perforated sleeve.

3. An oil cleaner comprising a rotatable drum, an upright spindleextending axially through the drum and to which the drum is fixed forrotation therewith on an upright axis, oil inlet pipes in the drumparallel to the spindle and radially spaced therefrom and from theperiphery of the drum, an oil inlet passageway in the lower portion ofthe spindle communicating with said oil inlet pipes for the delivery ofoil to be cleaned to the interior of said drum, said oil inlet pipesterminating with open ends in the upper portion of the drum, an outletpassageway for clean oil in the upper portion of said spindle andopening into the drum above the oil inlet passageway in the spindle, acylindrical filtering element rotatable with the drum and surroundnigthe spindle to lter oil flowing to the opening of the outlet passagewayfor clean oil, means for rotating said drum including at least onereaction nozzle having a tangential setting and arranged to deliveroutside the drum, and means for conducting oil from the upper portion ofsaid drum outside the cylindrical filtering element to the reactionnozzle, whereby the oil to be cleaned and delivered through said pipesinto the upper portion of the drum is subjected to the centrifugalaction produced by the rotation of the drum for the separation of dirt,which accumulates on the inner periphery of the drum, and oil flowing tothe opening from the drum to the outlet passageway in the upper portionof the spindle is passed through said cylindrical filtering element.

4. An oil cleaner comprising a rotatable drum, an upright spindleextending axially through the drum and to which the drum is xed forrotation therewith on an upright axis, an oil inlet passageway in thelower portion of the spindle, conduit means rotatable with the drumcommunicating with said oil inlet passageway for the delivery of oil tobe cleaned to the interior of said drum, said conduit means terminatingand having an outlet in the upper portion of the drum in spaced relationto its periphery and to said spindle, an outlet passageway for clean oilin the upper portion of said spindle and opening into the drum above theoil inlet passageway in the spindle, a cylindrical filtering elementsurrounding the spindle arranged to filter oil owing to the opening ofthe outlet passageway for clean oil, and means for rotating said drum,whereby the oil to be cleaned and delivered through said conduit meansinto the upper portion of the drum is subjected to the centrifugalaction produced by the rotation of the drum for the separation of dirt,which accumulates on the inner periphery of the drum, and oil owing tothe opening from the drum to the outlet passageway in the upper portionof the spindle is passed through said cylindrical filtering element.

References Cited in the file of this patent UNITED STATES PATENTS1,468,740 Paul Sept. 25, 1923 1,619,652 Carter Mar. l, 1927 1,714,658Carter May 28, 1929 2,087,778 Nelin July 20, 1937 2,257,107 CoberlySept. 30, 1941 2,650,022 Fulton et al Aug. 25, 1953 FoREIGN PATENTS2,420 Great Britain of 1912 13,074 Great Britain of 1914

